Railway-traffic-controlling system



L. V. LEiw|s. RAILWAY TRAFFIC CONTROLLING SYSTEM.

A PPL ICATION FILED MAR. 4. I918- V 1,405,527. Patented Feb. 7, 1922.

4 SHEETS-SHEET I.

lug-I I III L. v. LEWIS. RAILWAY TRAFFIC CONTROLLING SYSTEM.

APPLICATQON FIL ED MAR. 4-. I918.

Patented Feb. 7, 1922.

4' sums-sum 2.

NVENTOR s E s s E n n w L. V. LEWIS.

RAILWAY TRAFFIC CONTROLLING SYSTEM.

APPLlCATlON FILED MAR. 4. 19m.

1,405,527, Patented Feb. 7, 1922.

4 SHEETS-SHEET 3- WITNESSEs NVENTOR L. V. LEWIS. RAILWAY TRAFFIC CONTROLLING SYSTEM.

APPLICATION FILED MAR. 4. 19H].

Patented Feb. 7, 1922.

UNITED STATES PATENT OFFICE.

LLOYD V. LEWIS, 0F EDGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO- THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

Specification of Letters Patent.

Patented Feb. 7, 1922.

Application filed March 4, 1918. Serial No. 220,172.

T 0 all whom it may concern:

Be it known that I, LLoYn V. LEWIS, a citizen of the United States, residing at Edgewood Borough, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Railway Trafiic Controlling Systems, of which the following is a specification.

My invention relates to railway trafiic controlling systems, and particularly to systems of the type wherein traffic governing means located on a train or vehicle is controlled by energy received from the trackway.

One object of my invention is the provision of a system of this character by virtue of which two distinct indications may be transmitted to the vehicle and which can be applied to existing signaling systems with the fewest possible changes in, and additions of, apparatus. 7

I will describe certain forms of trafiic controlling systems embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of traflic controlling system embodying my invention. Fig. 2 is a view showing a modification of the system shown in Fig. 1 and also embodying my invention. Figs. 3 and 4 are views showing still'other modifications and also embodying my invention.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, the reference characters R, R designate the track rails of a railway, which rails are divided by insulated joints 2 to form blocks A-B, B-C, etc. Trailic along the railwa is normallyzin the direction indicated by t e arrow. stending along the tra-ckway is an auxiliary conductor X which is preferably, though not necessarily, located midway between the track rails as shown in the drawing. This auxiliary conductor is divided, by insulation 2' or otherwise, at points substantially opposite the insulations in the track rails, and is further divided in a similar manner at a point E within each block to form a rear and a forward section for the block. Thus within the limits of block A-B this auxiliarv conductor is divided into a rear section E and a forward section E-B.

Each block is provided with a track circuit comprising as usual the track rails of the block, a source of alternating signaling current connected across the rails adjacent the exit end of the block, and a track relay connected across the rails adjacent the entrance end of the block. The source of current for each track circuit is a secondary 3 of a transformer which is designated T with an exponent corresponding to the location, and the relay for each track circuit is designated by the reference character H. with an exponent corresponding to the location. For example. the track circuit for block B-C comprises the secondary 3 of transformer T and relay H Each secondary 3 is connected with the track rails by conductors 4 and 5, which conductors include respectively the two windings 6 and 6 of a reactor 'W, the faction of which will be explained hereinafter. The track relav H for each block is connected directly across the track rails of the block, as shown.

The primary windings of the several transformers T are connected with transmission mains P which extend along the railway and to which alternating signaling current is supplied by suitable means, such as by a generator N.

Means are provided for each block for supplying alternating signaling current to the corresponding forward section of the auxiliary conductor X, this supply being controlled by the track relay for the block next in advance so that such supply is discontinued when the block in advance is occupied. As here shown, this current is supplied by a secondary 7 of the transformer T at the exit end of the block, and is controlled by a contact 9 of the track relay for the b ock next in advance. The return circuit for the current in conductor X is completed through the track rails in such manner that said current does not interfere with the supply of track circuit current to the track rails from transformer secondary 3. For example, the circnit for the advance section E-B of the auxiliary conductor for block A-B is from the secondary 7 of transformer T, through wire 8, contact 9 of track relay H wire 10, resistance 11, wire 10', conductor X, to wire 12; the circuit then divides into two similar branches, one branch being through winding 13 of a readtor M, wire 14, rail R, wire 4 at location B, winding 6 of a reactor W, left-hand half of transformer secondary 3, and wire 15 to secondary 7. The other branch is from wire 12 through winding 13' of reactor M, wire 14, rail wire 5, winding 6" of reactor W, right-hand half of secondar 3, and wire 15 to secondary 7. The reactor Ni comprises the two windings 13 and 13 on an iron core 16, these win ings being so arranged that when equal currents flow therethrough in the manner just traced, that is, from conductor X to the track rails or vice-versa, the magnetic fluxes produced by the currents in the two windings oppose each other and so are neutralized, whereby this device offers a low l npedance to such current flow. The device ofi'ers high impedance, however, to the flow of track circuit current from rail to rail, be-

cause such flow is through the two windings 13 and 13 in series. The reactor 7 comprises the two windings 6 and 6 on an iron core 17, these windings beingso arranged that when currents flow therethrough from rails R and R to secondary 7 as described,

the fluxes produced by the two windings neutralize each other and so the device offers a low impedance to such current flow. The track circuit current, however, flows from secondary 3 through winding 6 to rail R and back through winding 6 (or vice-versa), hence as to this current the windin s 6 and 6 are in series and so the device ofi'ers considerable impedance to such current flow. One function of this device is to prevent an abnormal flow of current from secondary 3 when the track rails are bridged by the wheels and axles of a car or train. Another function will appear hereinafter.

The branch circuits from conductor X to secondary 7 just traced pass in opposite directions through the two halves of secondary 3. consequently secondary 3 will produce no electromotive force in the circuit of secondary 7. Likewise, since the circuit of secondary 7 is connected to the circuit of secondary 3 at two points both having an instantaneous potential midway between the potentials at the terminals of secondary 3, and hence having the same potential, it follows that secondary 7 will roduce no electromotive force in the circult of secondary 3.

Inasmuch as the supply of current to section E--B of the auxiliary conductor X is controlled by front contact 9 of the track relay for block B-C, it is apparent that this conductor section will be supplied with current only when block B-C is unoccupied.

Means are also provided for each block for supplying signaling current to the rear section of auxiliary conductor X for the block, this current supply likewise being controlled by the track relay for the block next in advance. The control in this instance is such, however, that current is constantly supplied to the rear conductor section, but that this current is of one relative polarity or the reverse according as the block next in advance is clear or occupied. For examplmwhen block B G is clear. so that relay H" is closed, the circuit for the rear conductor section A-E of block AB is from the left hand section of winding 18 of transformer T, through wire 19, front point of contact 20 of relay H, wire 21. resistance 22. wire 21, section A--E of conductor X, wire 12 thence in opposite directions through the two similar windings 13 and l3 of reactor Mat location A,the tworails R and R in multiple, thence in opposite directions through the two windings of reactor W at location B and of secondary 3 of transformer T wire 15 to the middle point of secondary 18. The action of reactors M and W and of secondary 3 on current flowing in this circuit is the same as the action of these devices on the current flowin through the forward section of conductor The current which is thus supplied to the rear conductor section I will term current of normal polarity. When track relay H is open, due to the presence of a car or trainin block B-C orto some abnormal condition, the current for conductor section A-E flows from the righthand half of secondary 18 of transformer T through wire 22'. back point of relay contact 20, thence as before to the middle point of secondary 18. This current I will term current of reverse polarity.

It will be clear, therefore, that the current in'conductor section AE will be of normal 100 or reverse polarity accordin as track relay H is energized or de-energized, that is, accordin as block BC is clear or is occupied. urtliermore, the currents in the sections of conductor X due to secondaries T 105 and 18 are displaced in phasev from the currents in the track circuits due to secondaries 3, because the circuits for the conductor sections include resistances 11 and 22, whereas the track circuits include the reactor W.

As shown in the drawing, block AB is occupied b a car or other railway vehicle, represente by an'axle and pair of wheeis V. Mounted on this vehicle in advance of the forward axle are three Usha ed lami- 116 nated iron cores 23, 24, and 25, eac core beingtransversely disposed with respect to the track rails with its legs pointing downwardly. The cores 23 and 24 are located directly above the track rails R and R, respec- 120 ively, whereas core 25 is located directly above the auxiliary conductor X. It is ap parent, therefore, that when alternating current flows in track rail R, some of the magnetic lines of force surrounding this rail will 125 pass through core 23 and so there will be an alternating magnetic flux in this core. Currents in rail R and in conductor X similarly create magnetic flux in cores 24 and 25, respectively.

Cores 23 and 24 are provided with coils 26 and 26, respectively, and core is provided with a coil 27. Alternating flux in any one of the cores will. of course. create an alternating difference of potential across the terminals of the coil on such core. (oils 2t; and 26 are included in series in a circuit which comprises coil 26. wire 2. coil 26*, wire 29. condenser 30. and wires 31. t and 33, which circuit I will. for convenience. designate circuit (1. (oils 2t; and it) are co n nectcd in this circuit in such manner that the potentials created by currents flowing in the. same direction in the track rails such as the current due to secondary T. neutralize each other and so cause no current in circuit a. but that the potentials created by currents flowing in opposite directions in the track rails, such as the current due to secondary 3. are additive. and so cause a flow of alternating current in circuit a. That component of the track current which flows in opposite directions in the two rails. therefore. induces alternating current in circuit a, but the currents supplied to the auxiliary conductor do not create current in circuit a be ause they comprise a component of the track current which flows in the same direction in the two rails.

(oil 27 is included in a circuit b. which circuit comprises the coil 27, wire 34. condenser 35, and wires 32 and 36.

Coils 26 and E26 are so wound as to have high inductance, and condenser 30 has comparatively small capacity. and the circuit including these elements (circuit a.) is tuned to resonance at the frequency of the signaling current, hence condenser 30 will be charged to a comparatively high potential by the comparatively feeble current induced in circuit a by current in the track rails. Circuit 6 is also tuned to resonance at the signaling current frequency, with similar results. It follows that when the vehicle V occupies a block in which signaling currents are supplied to the track circuit and to the auxiliary conductor X, currents will flow in circuits aand b on the vehicle, and these currents will he of the same frequency as. and will have the same phase displacement as. the currents in the track circuit and auxiliary conductor respectively. These currents, and the consequent potentials impressed on condensers 3t) and 35. are. however. too feeble to reliably actuate traffic governing apparatus of a rugged character. hence I preferably provide suitable amplifying or relaying apparatus. which. in the form here shown. comprises electron relays or amplifiers K. K. K and K. lCacb of these relays comprises a vacuum bulb 41 containing a filament It. a plate ll and a grid 39 interposed between the two. The filaments 39 of these relays are constantly heated by a battery 43 through circuits which will be obvious from the drawing.

Condenser 30 of circuit u is connected across the filament 3 and grid 39 of relay K, a blocking condenser 37 being included in the circuit. The plate circuit of relay l\" is from a battery -14. through wires -15 and 46. across the gap between filament 3H and plate 40 of relay K. primary of transformer 49. wire 43 to battery 44. condenser 47 is connnected across the terminals of the primary of transformer 49. the circuit including this condenser and the transformer primary being tuned to resonance at the frequency of the signaling current. The secondary of transformer 49 is connected a.cros\ the filament 38 and grid 39 of the electron relay K The plate circuit of this latter rclay is from battery 44 throu h wires 45. 31. 5t) and 51. the ga between lament 38 and plate 40 of relay T2 wire 52. winding ot' a relay F. and wire 54 to battery 44. (onnccted across winding 55 is a condenser 52%. the circuit comprising condenser 53 and winding 55 being tuned to resonance at the frequency of the signaling current. It will be seen. therefore. that relay winding will be supplied with current of the same frequency as that which is supplied to the track circuit. but that this current will be of considerably greater magnitude and so is of sufficient value to reliably actuate an electromagnetic or induction motor relay of rugged design.

The current induced in the \'tl\lt'lt--('tlll'it(l circuit 7) is similarly amplified by the two electron relays K and. K. the plate circuit of the latter relay being from battery 4-1. through wires 45, 31, and 56. the gap between the filament and the plate of relay K wire 57. winding 59 of relay F. thence through the wire 54 to battery 44. (onnected across winding 59 is a condenser 5H. \Vinding 59 is. therefore. supplied with cur rent of the same frequency and relative phase as the current supplied to the section of the auxiliary conductor X over which the vehicle happens to be. but the current in winding 59 is, of course. of considerably greater magnitude than that which flows in circuit 6.

The relay F is of the induction motor type. comprising a rotor member (it) which responds to currents displaced in phase in the windings and 59. and which. in turn. actuates a. contact member (31. Inasmuch as the currents in the track circuits and in the auxiliary conductor X are displaced in phase. it follows that the currents in relay windings 55 and 59 will similarly be displaced in phase. so that torque will be excrtcd on the rotor member (it) in one direc. tion or the other. depending on the relative instantaneous polarities of the currents induced in circuits a and b. In other words. contact member 61 will be swung in one direction or the other from its middle position to which it is biased, according as the current in circuit 1) has one instantaneous polarity or the other with relation to the current in circuit a, that is. according as the current in conductor section .-\-E is of normal or reverse polarity.

The relay F may be employed to control any kind of tral'lic governing apparatus that may be desired. As here shown. this relay controls a signal S comprising three incandescent lamps G, Y and R, which lamps when illuminated indicate proceed; "caution and stop, respectively. These lamps are supplied with current from a battery 98. \Vhen either or both windings of relay F are de-energized. so that contact member 61 occupies its intermediate position. contact til-62 closes the circuit for lamp R, which circuit will be obvious from the drawing. \Vhen both windings of relay F are energized and the current in winding 59 is of normal polarity, contact member 61 is swung to the left into engagement with contact 64. so that the proceed lamp G is illuminated. When both relay windings are energized and the current in winding 59 is of reverse polarity, contact 61-454 is closed, so that the caution lamp Y becomes illuminated. It will be seen, therefore. that signal S on the vehicle indicates stop, c-ailtion" or proceed. according as relay F is de-energized, energized in reverse direction. or energized in normal direction.

The operation of the system shown in Fig. 1 is as follows The block next in advance of location C is occupied by a vehicle which is represented by a pair of wheels and an axle V, so that relay H is de-energized. Current of reverse polarity is, consequently, supplied to the rear section BE of the auxiliary conductor for block B-C, whereas the forward conductor section E-C for this same block is de-energized. Track relay H is energized, so that forward conductor section E-B of block A-B is energized and current of normal polarity supplied to the rear conductor section A of this block. Vehicle V being over the rear conductor section of block AB, circuit a is supplied with current from the track circuit and circuit 6 receives current of normal olarity due to the current in the conductor Relay F is, consequently. energized in normal direction, so that signal S indicates proceed. As the vehicle V passes into the forward section of block AB, no change occurs, because, of course, the current supplied to the forward conductor section is of normal polarit \Vhen the vehicle V passes into block B- the circuit (a continues to be energized due to track circuit current, but ourrent of reverse polarity is now supplied to circuit 6. Relay F, therefore, becomes energized in reverse direction. so that lamp Y becomes illuminated and signal S indicates caution. After the vehicle passes point E in block B-C', the circuit b becomes de-energized. so that relay F likewise becomes deenergized, whereby lamp R becomes illuminated so that signal S then indicates t p 77 Assuming that vehicle V remains in the position shown and that the block in advance of the one occupied by this vehicle is unoccupied, it follows that the rear conductor section of the block occupied by vehicle V is supplied with current of normal polarity. Those portions of the track rails of this block which are in the rear of vehicle V are not supplied, however, with track circuit current because this current is shunted by the wheels and axles of vehicle V. If. therefore, vehicle V enters the block occupied by vehicle V, winding 59 of rela v F will become energized, but winding 55 will become tie-energized. so that relay F will continue to be tie-energized and so signal S will continue to indicate stop.

In the system shown in Fig. 1. the relative polarity of the currentin the track circuits is always the same, that is, the track circuits are of the type which is generally known as non-polarized. This system, then, is readily adapted for application to a railway which is already equipped with a signaling system embodying alternating current track circuits of the non-polarized type. \Vhen it is desired to apply a system embodying my invention to a railwa which is already provided with a signaling system comprising polarized alternating current track circuits. the system shown in Fig. 2 may be preferable. This system does not interfere with the existing roadside signals, or with the control of these signals by the existing three-position alternating current track relays. The substantial difference between the systems shown in Figs. 1 and 2. so far as the present invention is concerned. is that in Fig. l the relative polarity of the track circuit current is constant and that of the current in the rear sections of the auxiliary conductor X is reversible, whereas in the system shown in Fig. 2 the polarity of the track circuit current is reversible and that of the currents in the auxiliary conductor X is constant.

Referring now to Fig. 2, the arrangement of blocks and of auxiliary conductor sections is the same as that shown in Fig. 1. In Fig. 2. however, each track relay, which is here designated by the reference character J with an exponent corresponding to the location, is of the three-position type. comprising two windings 65 and 66. the former of which is connected directly with the track rails and the latter of which is constantly supplied with alternating current from the left-hand section of secondary UT of the adjacent transformer '1. Each of these rela 's. therefore. responds to reversals of the relative polarity of the current in the corresponding track circuit with respect to that of the transmission line I: in other words. the contact fingers (58. (3S) and TH of each relay are swung to the left when the polarity of the track circuit is normal. and to the right when the polarity of the track circuit is reverse. and these contact lingers occupy vertical or intermediate positions when the track winding of the relay is tic-energized. Located at the entrance of each block is a roadside signal which is designated by the reference character 5 with an exponent corresponding to the location of the signal. As here shown. these signals are of the type known as light signals." each comprising three electric lamps. G. Y and R. indicating proceed." caution and stop.' respectively. when illuminated. Zach signal S is controlled by contact finger 68 of the adjacent track relay in such manner that lamp G is illuminated when the relay is energized in the normal direction. lamp Y is illuminated when the relay is energized in reverse direction. and lamp It is illuminated when the relay is tie-energized. These lamps are supplied with current from the left-hand section of secondary 67 of the adjacent transformer, and the circuits will be obvious from the drawing without further explanation.

The suppl of current to the track circuit of each blocft is controlled by contact (59 of the track relay for the block next in advance, in such manner that the polarity of the track circuit current is normal when the relay is energized in either direction. and reverse when the relay is de-eiiergized. The immediate source of supply for each track circuit is a transformer designated by the reference character T1 with an exponent corresponding to the location. the secondary of which transformer is connected across the track rails through a reactor \V. The circuit for the primary of the transformer T1". when relay J is deeiiergized. is from the middle terminal of secondary 6T of transformer T through wire T2. primary of transformer 71 wire T3. contact finger (it) of relay J and wire T4 to the right-hand terminal of transformer secondary 67. The current which is thus supplied to the track circuit of block B--( is of reverse polarity. When relay J is energized in either normal or reversed direction. the circuit for the primary of transformer T1 is from the middle terminal of secondary 67 of transformer T through wire T2. primary of transformer TI wire T3. contact linger 69. contact 81 or 82, wire 83 and wire T6 to the left-hand terminal of transformer secondary 67. The

current which is then supplied to the track circuit of block B-C is of normal polarity.

The current for the advance section of conductor X in each block is supplied from the right-hand section of secondary 67 of the transformer 'l' at the exit end of such hlock through a transformer which is designated hy the reference character T8 with an exponent corresponding to the location, and this supply is controlled by contact T0 of the track relay for the block next in advance. The primary circuit for transformer TH". for example. is from the middle point of secondary 6T of primary T. through wire T2. primary of transformer T8", wire TT. contact finger T0, and wire 76 to the left-hand terminal of secondary 6T. It will he seen that this circuit will be closed when track relay J is energized in either direction. but opened when this track relay is tie-energized. The secondary circuit for transformer T8 is from the secondary of this transformer through wire T9. resistance 8!). conductor section E(. reactor M at the rear end of such conductor section. rails 1t and R in multiple, wires 84 and S5 in multiple. the windings of reactor W in multiple. the two halves of ,the secondary of transformer T1 in multiple. and wire 80 to the secondary of transformer T8".

The rear section of conductor X for each block is supplied with current from a secondary T5 of the transformer T at the entrance end of such block. For example. the circuit for section BE of this conductor in block Ii( is from secondary T5 of transformer T". through wire '86. resistance 87, conductor section BE in block B(. reactor M at the forward end of such conductor section. rails R and R in multiple, reactor M at the rear end of said conductor section. and wire 88 to secondary 75. It will he seen. therefore. that current is constantly supplied to this section of the auxiliary conductor X.

()wing to the fact that the track circuit current must pass through reactors \V in such direction that these devices are reactive to such current. and to the fact that the currents .for the sections of conductor X must pass through resistance 87 or 89. it follows that the track circuit current and the currents in the auxiliary conductors are displaced in phase.

The apparatus on the vehicle V in Fig. 2, is similar to that shown in Fig. 1. except that in Fig. 2 I have shown only one electron relay for each winding of the vehicle governing relay F. (ondenser 30 In circuit a is connected with the filament and grid of relav K. whereas condenser 35 of circuit I) is connected with the filament and grid of relay K Relay winding 55 is connected in the plate circuit of electron relay K, and relay winding 59 is connected in the plate circuit of electron relay K I have shown only two electron relays in Fig. 2 to indicate that this arrangement may be used instead of that shown in Fig. 1, if considered desirable. It is understood, however. that the single pair of electron relays may be used in combination with the trackway circuits shown in Fig. 1. and that likewise two pairs of such relays may be used in combination with the trackway circuits shown in Fig. 2.

The operation of the system shown in Fig. 2 will now be readily understood and may be briefly explained as follows:

nasmuch as the block directly in advance of location is occupied by vehicle track relay J is deenergized, so that signal S indicates stop and the polarit of the track circuit current in block 13- is reverse. Conductor section E-( of this block is tie-energized. but conductor section BE of the same block is. of course, energized. Track relay J is. consequently, energized in reverse direction. so that signal S indicates caution. The polarity of the track circuit current in block .\B is normal. and both conductor sections for this block are energized. The vehicle V being in block A B, relay F is energized in normal direction. so that signal S indicates proceed. As this vehicle enters block B(. the polarity of the current in its circuit a will be reversed, so that signal S will change to caution, As the vehicle enters section E-C of this block. current will cease to flow in circuit 1), so that relay F will become tie-energized, and, consequently, signal S will indicate stop.

Referring now to Fig. 3. the arrangement of blocks and auxiliary conductor sections is the same as that shown in Fig. 1. The track circuits are likewise the same as those shown in Fig. 1, except that the reactors W' are. omitted and a single reactance 90 is included between each transformer secondary 3 and one of the track rails. The control of the supply of current to the sections of conductor X is different from that shown in Fig. 1, however, and is as follows:

The rear conductor section for each block is connected in series with the forward section of the block in the rear, and current of normal or reverse polarity is at times supplied to these two sections simultaneously. Considering, for example. section B-E of block BC and section E-B of block AB, and assuming that track relays H and H are energized, the circuit is as follows: From the left-hand terminal of secondary 18 of transformer T through wire 19 front point of contact 20 of relay H wire 21, resistance 2:2. wire 21, conductor section BE of block l-C wire 91. con tact 9 of relay H wire 92, conductor section EB of block A-B, reactor M at the rear end of this conductor section, rails R and R in multiple, reactor M at the forward end of the latter conductor section, wire 93, reactor M at the rear end of section BE, rails R and R of block BC in multiple, reactor M at the forward end of section E-C. and wire 93 to the middle terminal of secondary 18. The current which flows in this circuit is of normal polarit When track relay H is tie-energized, t e circuit is from the right-hand terminal of secondary 18 of transformer T through wire 22. back point of contact 20 of relay H and then through the remainder of the circuit as before. The current which then flows in the auxiliary conductor sections is of reverse polarity.

The operation of the system shown in Fig. 3 is as follows:

The block immediately in advance of location C being occupied by a vehicle V, track relay H is (lo-energized, so that conductor section FC is de-energized by virtue of the fact that contact 9 of relay H is open. The back point of contact 20 of this same relay being closed, current of reverse polarity is supplied to the rear conductor section of block B-C and to the forward conductor section of block A-B. The rear section of block A-B is occupied by a vehicle V, which is equipped with traffic governing apparatus which may be similar to that shown in Fig. 1, or to that shown in Fig.2. Relay H being energized, the auxiliary conductor section under this vehicle V is'i'eceiving current of normal polarity so that the signal on such vehicle indicates proceed. As this vehicle passes point E in block A-B, the current in the circuit 1; therein becomes reversed, so that the si nal on the vehicle changes to caution indication. This signal continues to indicate caution after the vehicle passes point B, and until it reaches point E in block BC. After assing this latter point, the vehiclecarried circuit b becomes de energized, so that the signal on the vehicle changes to stop indication.

It will be seen that the system shown in Fig. 3 provides for an overlap so far as the vehlcle governing apparatus is concerned, that is, that a caution indication is received on the vehicle at some distance in the rear of the block in the rear of an occupied block, and that a. stop indication is received on the vehicle at a point some dis tance in the rear of an occupied block.

In the systems shown in Figs. 1, 2 and 3. it will be noted that the current which is supplied to the auxiliary conductor returns through the track rails, this current flowing in the same direction in the two rails. It follows, then, that instead of collecting this current from the auxiliary conductor it may, if desired, be collected from the track rails,

and in Fig. 4 I have illustrated one form of system in which this is done.

Referring now to Fig. 4. the track rails R and R are divided into blocks -B. B--(', etc.. as in the preceding views. and each block is provided with a track circuit comprising a transformer secondary 3 and a track relay H exactly as in Fi l. The vehicle V is provided with a circuit (1 in which current is induced by virtue of the component of the track current which flows in opposite directions in the two rails. and this current in circuit (1 causes the energization of winding 57 of relav I through the medium of electron relay K. Thus far the apparatus is substantially the same as that shown in Fig. 1.

Means are provided for each block for supplying a second alternatin, current thereto. which current flows in the same direction in both rails of the block. and the polarity of which current is normal or reverse according as the next block in advance is free or occupied. For example. when track relay H is energized. the path of this current in block l-( is from the left-hand terminal of secondary lb of transformer through wire 93. front point of contact 21 of relay ll. wire 94. reslst-ance .22. wire 94", reactor M at location 13. thence through the two rails R and R of block B-( in multiple to location t. thence in multiple through the windings of reactor \Y and the two halves of transformer secondary 3. wire 95. contact 9 of relay ll". and wire 96 to the right-hand terminal of transformer secondary 18. The current which flows in this circuit is of normal polarity with respect to the track circuit current supplied by secondary 3. Then relay H is dwenergized. the path of the current in block B-C is from the right-handterminal of secondary 18 of transformer T. through wire "ti. back point of contact 20 of relay H. wire SH. resistance 22. wire 94. reactor M at location B. thence through rails R and R in multiple to point E in block l(. thence through the windings of reactor M at this point. wire 9?. resistance ll. and wire 97. to the middle point of secondary in. The current which flows in this circuit is of reverse polarity with respect to the track circuit current and it will be noted that it flows in the track rails only between points B and E in block section B C.

The vehicle is provided with two laminated soft iron cores :25 and '25 disposed above rails It and B respectively. and which cores are preferably located in the rear of the vehicle. These cores carry windings 27 and 27 respectively. which windings are included in series in the vehicle-carried circuit F. The windings :27 and 2?" are so arranged that the currents induced therein by currents flowing in the same direction in the track rails are additive so that such track currents produce an alternating current in circuit 1). Tlll current in circuit 6 causes alternating current to be supplied to winding 5!) of relay 1 through the medium ()1 electron relay K.

The operation of the system shown in Fig. -l. is as follows:

The block in advance of location C being occupied by vehicle Y. track relay H is deenergized. so that current of reverse polarity is supplied to the track rails of block B-C between points I3 and E from secondary 18 of transformer T. Track relay H being energized. current of normal polarity is supplied to the rails of block .\B from secondary 18 of transformer T Relay F on vehicle Y is, consequently. supplied with currents of such phase relation that this relay is energized in normal direction. As the vehicle Y proceeds past point E in block .-\-B. no change occurs in the vehicle-carried apparatus. but as the vehicle passes point B. the relative polarity of the current supplied to circuit 0 is reversed. so that relay F becomes reversely energized. As the vehicle passes point B in block B-C. the supply of current to the circuit 1) is discontinued. so that relay F becomes de-energized.

One important feature of the systems shown herein is that they providc for transmitting two distinctive signals to a vehicle with the use of signaling current of but one frequency. For this reason. the invention is easily applied to a railway which is already equipped with a signaling system embodying alternating current track circuits. the only substantial changes which are necessary bein the installation of the auxiliary conductor the reactors M and \V. and suitable equipment on the cars or trains. An alternating current transmission line is already in existence in such instances. and this line can he used to supply all the trackway current required for the entire vehicle control and signaling system.

Although I have herein shown and dcscribed only certain forms of railway traffic controlling systems embodying my invention. it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described what I claim is:

1. Railway traffic controlling apparatus comprising track rails. an auxiliary conductor parallel therewith. means for supplying alternating currents to said rails and conductor. means controlled by trafiic conditions for varying the character of one of said currents. means for procuring on the vehicle two currents having the same my invention.

haracteristics as the trackway currents, and vehicle-carried trafiic governing means colitrollcd jointly by the currents produced on the vehicle.

Railway traflic controlling apparatus comprising track rails. an auxiliary condncior parallel therewith. means for supplying alternating currents to said rails and conductor. means controlled by traflic conditions for varying the phase of one of aid currents with respect to the other. and vehicle-carried traflic governing means controlled by the phase relations of said currents and by the presence and absence of said currents.

ii, In combination, a railway track divided into blocks. an auxiliary conductor for each block. means for each block for supplying alternating currents to the track rails and to the auxiliary conductor for the block. means for each block controlled by traliic conditions in advance for reversing the relative polarity of the current in the track rails, and vehiclecarried trailic govcrning means controlled by said currents and by the phase relations of said currents.

'1'. Railway traffic controlling apparatus comprising track rails, means for supplying two alternating currents thereto. a vehicle-carried traffic relay having two windings. and requiring currents in both windings to give a proceed signal. and vehiclecarried means controlled selectively by said two currents in the track rails for supplying alternating currents to said two windings.

Railway traffic controlling apparatus comprising track rails. means for applying an alternating difference of potentia across said rails. and another alternating difl'ercncc of potential along said rails. and rehicle-carried traflic governing means controlled jointly by the currents in said track rails due to said potential differences.

6. Railway traiiic controlling apparatus comprising track rails. a source of alternating signaling current connected across said rails. a second trackway circuit including a second source of alternating signaling current, a vehicle-carried relay having two windings, and vehicle-carried means controlled by said trackway currents for supplying alternating currents to said two relay windings.

7. Railway trailic controlling ap aratus comprising track rails. a source of a ternating signaling current connected across said rail a second trackway circuit including a second source of alternating signaling current. a vehicle-carried relay having two windings. and vehicle-carried means controlled by said first trackway current for suppl vin; alternating current to one winding of said rela v and other vehicle-carried means controlled by current in said second trackway circuit for supplying alternating current to said other relay winding.

8. Railway traliic controlling apparatus comprising track rails. means for supplying two alternating currents thereto, one of which flows in opposite directions in the two rails and the other of which flows in the same direction in the two rails, a vehiclc-carricd relay having two windings, and vehicle-carried means controlled by said two currents respectively in the two track rails for supplying alternating currents to said two windings.

9. Railway traliic controlling apparatus comprising track rails. means for supplying two alternating currents thereto. one of which flows in opposite directions in the two rails and the other of which flows in the same direction in the two rails, traffic governino" means on a vehicle comprising two windii gs. vehicle-carried means controlled by one only of said currents in the rails for supplying alternating current to one of said windings. and other vehicle-carried means controlled only by the other current in the rails for supplying alternating current to the other winding.

1U. Railway traffic controlling apparatus comprising means for supplying alternating currents differing in phase to the trackway, a relay carried on a train and having two windings. and means also on the train controlled by said currents in the trackway for supplying alternating currents to the windings of said relay of the same relative phases as the currents in the trackway.

11. Railway tratlic controlling apparatus comprising a relay carried on a vehicle and having two windings, means also on the vehicle forsupplying currents differing in phase to said two relay windings, and means located in the trackway for selectively controlling said means.

12. In combination, a block of railway track. an auxiliary conductor, means for supplying one alternating signaling current to the track rails of said block, means for Supplying another alternating signaling current to said rails and said conductor. and vehicle governing means controlled by said two currents.

13. In combination. a block of railway track, an auxiliary conductor for said block. a vehicle controlling circuit the two sides of which are formed by the two track rails of said block. a second vehicle controlling circuit one side of which includes said two rails in multiple and the other side of which comprises said auxiliary conductor. and means for sul'iplying alternating currents to said two circuits.

14. In combination, a block of railway track. an auxiliary conductor. means for supplying one alternating signaling current to the track rails of said block, means for supplying another alternating signaling current to said rails and said conductor, means controlled by traflic conditions in advance for changing the relative polarity of one of said currents. a railway vehicle. a relay on said vehicle having two windings and a movable member operated in one dircction or another according to the phase relation of the currents in said windings. and means on the vehicle for supplying to said relay windings currents having the same relative polarity as the currents in the track rails.

15. In combination. a block of railway track. a trackway circuit comprising the two track rails of said block in series, a second trackway circuit comprising said two track rails in multiple. means for supplying alternating currents to said circuits, and train carried trailic governing means controlled by the currents in said traclnvay circuits.

16. In combination, a block of railway track, a trackway circuit comprising the two track rails of said block in series, a second trackway circuit comprising said two track rails in multiple. means for supplying alternating currents of the same frequency but differing in phase to said two trackway circuits, and vehicle carried traffic governing means controlled by the currents in said circuits.

17. In combination. a block of railway track. a trackway circuit comprising the two track rails of said block in series, a second trackway circuit comprising said two track rails in multiple. means for supplying alternating currents of the same frequency but differing in phase to said two trackway circuits. a vehicle carried relay having two windings. means on the vehicle for supplying alternating currents to said windings having the same phase displacement as the currents in said two trackway circuits.v and traflic governing means on the vehicle controlled by said relay.

18. In combination. track. a trackway circuit comprising the two track rails of said block in series. a second trackwa y circuit comprising said two track rails in multiple, means for supplying alternating currents of the same frequency to said two trackway circuits, means for reversing the relative polarity of the current in one of said circuits, and vehicle carried tral'iic governing means controlled by the currents in said trackway circuits and responsive to the relative polarity of said currents.

19. In combination. a block of railway track. a trackway circuit comprising the two track rails ol said block in series. a second trackway circuit comprising said two track rails in inultiple. means for supplying alternating currents of the same frequency to a block of railway other times connectin the .ondary 1S. and train carried said two trackway circuits, means for reversing the relative polarity of the current in one of said circuits. a vehicle carried rclay having two windings. means on the vehicle for supplying to said two windings alternating currents having the same relative polarity as the currents in said trackway circuits. and trailic governing means on the vehicle controlled by said relay.

2H. In combination. a block of railway track. a trackway circuit comprising the two track rails of said block in series, a second trackway circuit comprising said two track rails in multiple. means for supplying alternating currents of the same frequency to said two trackway circuits. means for reversing the relative polarity of the current in one of said circuits, a vehicle carried relay having two windings and a member movable in one direction or another according to the relative polarity of the currents in said windings. means on the vehicle for supplying to said two windings alternating currents having the same relative polarity as the currents in said trackway circuits, and trafiic governing means trolled by said movable relay member.

21. In combination, a block of railway track. a transformer secondary 3 connected across the track rails of said block adjacent the exit end. a first impedance connected across the rails adjacent the entrance end of said block, a second impedance connected across the rails at an intermediate point in said block, a transformer secondary 18 the middle point of which is connected with the middle point of said second impedance, means controlled by traffic conditions in advance of said block for at times connecting the middle point of said first impedance with one terminal of said secondary 18 andthe middle point of said secondary 3 with the other terminal of secondary 1S. and for at middle point of the first impedance with the last-mentioned terminal of secondary 18 and disconnecting the middle point of secondary 3 from sectrafiic governing means controlled by the currents flowing in the track rails from said transformer secoinlaries.

22. In combination. a block of railway track. means for applying an alternating dili'erence of potential across the rails adjacent the exit end of said block. means for applying a second alternating difference of potential along the rails from the entrance end of the block to an intermediate point in the block. or from the entrance end to the exit end of the block, and vehicle carried traflic governing means controlled by the currents flowing in said track rails due to aid potential difl' crences.

23. In combination. a block of railway track, means for applying an alternating on the vehicle cori-' difference of potential across the rails at the exit end of said block. means for applying a second alternating difi'erencc ofpotential of the same frequency but of one relative polarity along the rails of a portion of said block or of the reverse relative polarity along the rails of the entire block. and vehicle carried tratlic governing means controlled by the curlents in the rails due to said potential differences and by the relative polarities of said currents.

.24. In combination. a block of railway track. a source of alternating current connected across the rails adjacent the exit end of said block. a second source of alternating current connected along the rails from the entrance end to an intermediate point in said block or from the entrance end to the exit end of said l)lt!t'l{. and vehicle carried trailic governing means controlled by the currents in the track rails from said sources.

25'. In combination. a block of railway track. a trackwav circuit comprising the two track rails of said block in series. means for supplying alternating' current to said circuit. a second trackway circuit controlled by traffic conditions in advance and including in multiple the two rails of a iortion of said block or of the entire l)i()('l according to said tratiic conditions. means for supplying to said second circuit alternating current of the same frequency as to the first. and vehicle carried traiiic governing means controlled by the currents in said two trackway circuits.

26. In combination. a block of railway track. a trackway circuit comprising the two track rails of said block in series. means for supplying alternating current to said circuit. a second trackway circuit controlled by traffic conditions in advance and including in multiple the two rails of a portion of Said block or of the entire block according to said traiiic conditions. means for supplying to said second circuit alternating current of the same frequency as to the first. a vehicle carried relay having two windings. means on the vehicle controlled by currents in said two trackway circuits for supplying currents to said two relay windings respectively. and traiiic governing means on the vehicle controlled by said relay.

2?. in combination. a block of railway track. a trackwav circuit comprising the two track rails of said block in series. means for supplying alternating current to said circuit. a second trackway circuit controlled by traffic conditions in advance and including in multiple the two rails of a portion of said block or of the entire block according to said traflic conditions. means for supplying to said second circuit alternating current of the same frequency as to the first. means for reversing the iclative polarity of the current in one of said circuits. and vehicle governing means on a vehicle controlled by the relative polarity of the currents in said two circuits.

2h. In combination. a. block of -ailway track. a trackway circuit comprising the two track rails of said block in series. means for supplying alternating current to said circuit. a second trackway circuit controlled ll tratiic conditionsin advance and including in multiple the two rails of a portion of said block or of the entire block according to said traflic conditions, means for supplying to said second circuit alternating current of the same frequency as to the first. means for reversing the relative polarity of the current in one of said circuits. a vehicle carried relay having two windings. means on the vehicle for supplying to said windings alternating currents having the same relative polarity as the currents in said trackway circuits. and traffic governing means on the vehicle controlled by said relay.

29. Railway tratlic controlling apparatus comprising track rails. a tracltway circuit comprising the two rails in series and a source of alternating current. a second trackway circuit including the two rails in multiple and a second source of alternating current of the same frequency as the first. a reactive impedance in one of said circuits and a non-inductive impedance in the other circuit, and vehicle-carried tratiic governing means controlled by the currents in said trackway circuits.

30. Railway traiiic controlling apparatus comprising track rails. a trackway circuit comprising the two rails in series and a source of alternating current. a second trackway circuit including the two rails in multiple and a second source of alternating current of 'the same frequency as the first. means for causing phase displacement of the currents in said circuits. and vehicle carried traiiic governing means controlled by the currents in said circuits.

31. Railway trafiic controlling apparatus comprising track rails. a trackway circuit comprising the two rails in series and a source of alternating current. a second trackway circuit including the two rails in multiple and a second source of alternating current of the same frequency as the first. means for causing phase displacement of the currents in said two circuits. means for reversing; the relative polarity of the current in one of said circuits, and vehicle carried tratiic governing means controlled by the currents in said two circuits and responsive to the phase relation of such currents.

32. Railway trafiic controlling apparatus comprising track rails. a trackway circuit comprising the two rails in series. a second trackway circuit con'iprising the two rails in multiple. means for supplying to said circuits alternating, currents of the same frequency but differing in phase, and vehicle carried traflic governing means controlled by the currents in said two circuits.

In combination, a block of railway track, two impedances connected across the track rails at different points in the block. means for connecting the two terminals of a source of alternating current with the middle points of said two impedances, means for connecting the two terminals of a second source of alternating current across the rails adjacent the exit end of the block, means for causing phase displacement of the currents from said two sources, and vehicle carried traffic governing means controlled by the currents flowing in the rails.

34. In combination, a block of railway track, a first impedance connected across the track rails adjacent the entrance end of the block, a second impedance connected across the rails at an intermediate point in the block, a third impedance connected across the rails adjacent the exit end of the block, means controlled by traffic conditions in advance of said block for applying an alternating difference of potential to the middle points of the first and second impedances or to the middle points of the first and third impedances, means for creating an alternating difference of potential across the track rails adjacent the exit end of the block, and vehicle carried trafiic governing means controlled by the currents in the track rails due to said differences of potential.

35. In combination, a block of railway track, a first impedance connected across the track rails adjacent the entrance end of the block, a second impedance connected across the rails at an intermediate point in the block, a third impedance connected across the rails adjacent the exit end of the block, means controlled by traflic conditions in advance of said block for applying an alternating difl'erence of potential to the middle points of the first and second impedances or to the middle points of the first and third impedances, means for creating an alternating difference of potential across the track rails adjacent the exit end of the block, the two differences of potential thus applied to the rails being of the same frequency but displaced in phase, means controlled by tratfic conditions in advance for reversing the polarity of one of said potential differences, and vehicle carried traflic rents in the track rails o on the two rails of the entire block in multiple, means for supplying to said second circuit alternating current of the same frequency as to the first circuit but of one relative polarity or the other according as the circuit includes a portion or all of the block, and vehicle carried traffic governing means controlled by the currents in said trackway circuits and responsive to the relative polarity of said currents.

37. In combination, a block of railway track, an auxiliary conductor, means for supplying one alternating signaling current to the track rails of said block, means for supplying another alternating signaling current to said rails and said conductor, means controlled by trafiic conditions in advance for varying the relative polarity of one of said currents, and vehicle carried means controlled by said trackway currents and arranged to give a proceed or a cantion signal according as said currents have one relative polarity or the other and a stop signal in the absence of either current.

38. Railway trafiic controlling apparatus comprising a. block section of a railway track, a source of alternating current connected across the rails adjacent the exit end of the block, means for causin a second alternating current to flow in t e same direction along the two rails of the block from the entrance end to an intermediate point in the block or from the entrance end to the exit end of the block, means for reversing the polarity of one of said sources of current, and vehicle carried traffic governing means controlled b said two curthe block.

In testimony whereof I aflix my signature in presence of two Witnesses.

LLOYD V. LEWIS.

Witnesses:

A. HERMAN Wnomm,

P. 0mm. 

